A single-shot revolver generally comprises a weapon frame and a barrel, a hammer or cock pivotally mounted on its shaft in the frame, and a trigger also pivotally mounted on its shaft in the frame. The two shafts or axes of rotations, respectively, extend parallel to each other and perpendicular to the barrel axis.
The hammer can be pivoted or swung from its rest or first position, against the force of a hammer spring, into a second position in which it is held under tension, or is tensioned or cocked by the hammer spring.
The hammer actuates a striker or firing pin, and movement of the hammer urges the trigger to swing from its rest or first position, against the force of the respective trigger spring, into a second position corresponding to the ready-for-firing condition of the weapon. When it is in this condition, the trigger precludes movement of the hammer, and the hammer or cock is maintained in its tensioned position or cocked. In other words, the trigger is set for firing when the weapon has been cocked.
The weapon also includes a cylinder with several cartridge chambers. This cylinder is mounted in the frame so that it can rotate about its shaft axis which extends parallel with respect to the barrel axis. A detent latch holds the cylinder in its positions. The detent latch engages cylinder catches arranged exteriorly at the cylinder, and the cylinder, accordingly, is capable of being indexed, i.e. of being stepped to bring succeeding cartridge chambers in line with the barrel.
A trigger bar or rod is kinematically connected or linked to the trigger, and when the trigger is pulled for firing, the trigger bar is moved or shifted in substantially longitudinal direction in the weapon frame. The upper free end of the trigger bar is positioned between the firing pin and the hammer when the trigger has assumed the ready-to-fire position. The rebounding hammer moves the striker by way of the free end of the trigger bar in axial direction causing firing of the weapon. At the end of the rebounding movement, the hammer is in its rest or first position.
The weapon also includes a lock which prevents pulling of the trigger when the hammer is in its rest position. This lock includes a lock part which is operative between the trigger and the ahmmer. The lock part can assume a locking or first position when the trigger and the hammer are in their respective rest positions, and movement of the trigger is then blocked. The lock part releases or frees the trigger during movement of the hammer from its rest or first position into the cocked or tensioned position (second position). Accordingly, the trigger can then be moved or swung into the ready-to-fire or second position, and the lock part leaves its locking or first position. When the hammer has returned to its first or rest position, the lock part also returns to its locking or first position during swinging back of the trigger from the ready-to-fire position into its rest or first position, and the trigger is blocked again by the lock part.
U.S. Pat. No. 3,777,384 describes a safety mechanism of this type for a revolver with a drum. The lock part in the prior art revolver is formed by the trigger bar. When the trigger of this prior art revolver is in its rest position, the trigger bar contacts a detent projection or formation of the hammer and, accordingly, movement or swinging of the trigger into the ready-to-fire (firing readiness) position is prevented. The trigger bar also engages in the detent projection, either with a corresponding detent projection or formation, or with the smooth frontal face of its free end. Moving the hammer into the tensioned position causes the hammer detent projection to be placed such that it is out of the reach of the trigger rod, i.e. the free end thereof. The trigger bar is then free to reciprocatingly move in its longitudinal direction. Accordingly, the trigger can then be swung to assume the second or ready-to-fire position.
Independently of the particular configuration of the trigger bar, the detent projection at the hammer must, in any case, be provided at the end which is remove from its pivot or swing axis. This is due to the fact that only at this free end can reliably occur (a) the detent engagement of the trigger bar in the detent projection, especially after firing a shot, on the one hand, and (b) disengagement of the detent projection during tensioning of the hammer, on the other hand.
Accordingly, the lock which ensures the safety function is provided in that part of the weapon in which the transfer of force or forces from the hammer to the firing pin arises. In this region the cartridges are fired and gases are formed which can contaminate and detrimentally affect the operation of the weapon. This region of the weapon, furthermore, and at least when the hammer is in the tensioned or cocked position (second position), is freely accessible.
Accordingly, during handling of the weapon, for example when changing cartridges, this region is very likely to become soiled and gather dust and dirt on the one hand and can be so manipulated that the intended locking function or effect, either unintentionally, for example when dirt accumulates at the detent projection, or even intentionally will fail. The safety of the weapon in either case would be noticeably and detrimentally affected.